Research On The Technology Of Macro-Based Data Conversion In Reverse Engineering

As a modern design methodology, reverse engineering has become an essential tool for industrial product development and innovation. Feature based reverse modeling strategy can be used to capture the original design intentions accurately and to guide the reverse modeling process conveniently. The technology of macro-based data conversion, focusing on the 2D sketch data and 3D surface data, is intensively explored to improve the data conversion between the feature-based reverse modeler RE-SOFT7.0 and the general CAD system NX 3.0 in this dissertation.For the sake of capturing the original design intentions from the products, two integrated solutions to reconstruct solid model from point cloud were presented in RE-SOFT7.0 according to the definition and the classification of the features in reverse engineering. One is based on sectional features, and the other is based on surface features. Both of them complete the theories and methods of CAD modeling in reverse engineering. On the other hand, the technology of General CAD modeling has been highly developed coming through several important phases such as Wireframe Modeling, Surface Modeling, Solid Modeling, Feature Modeling, Parametric Modeling and Variation Modeling. Combining the two technologies can accelerate the reconstructions of product CAD models, which could be used in corresponding phases of the product lifecycle management (PLM). So it really makes sense to find a convenient and effective way to convert data between reverse engineering CAD systems and general CAD systems.A macro file, which is used to record and replay the process of a series of operations in CAD systems, can translate the designing process of one product in one CAD system to that of another system, so no data losing occurs. The original design intentions captured in RE-SOFT7.0 are expressed as key feature parameters and constraints of curves and surfaces. So, the data conversion between RE-SOFT7.0 and a general CAD system can be conveniently actualized by transforming those feature parameters and constraints to macro commands of corresponding feature forming operations. Using the macro-based method, CAD systems, which need to convert data to one another, don't need to have similar geometric representations. That makes it much easier to develop conversion interfaces. The research work related to this dissertation has made it available to convert data, including 2D sketch data and 3D surface data, from RE-SOFT7.0 to NX 3.0.